abstract class A {
	abstract protected void x();
	abstract void y();
}

class B extends A {
	protected void x() {
		System.out.println("x");
	}
	void y() {
		System.out.println("y");
	}
}

class Main {
	public static void main(String[] args) {
		B b=new B();
		b.x();
		b.y();
	}
}
